diff --git a/ruoyi-modules/management-platform/src/main/java/com/ruoyi/platform/service/impl/WorkflowServiceImpl.java b/ruoyi-modules/management-platform/src/main/java/com/ruoyi/platform/service/impl/WorkflowServiceImpl.java
index 6d912051..84a60642 100644
--- a/ruoyi-modules/management-platform/src/main/java/com/ruoyi/platform/service/impl/WorkflowServiceImpl.java
+++ b/ruoyi-modules/management-platform/src/main/java/com/ruoyi/platform/service/impl/WorkflowServiceImpl.java
@@ -142,8 +142,16 @@ public class WorkflowServiceImpl implements WorkflowService {
     public WorkflowVo update(WorkflowVo workflowVo) throws Exception {
         Workflow workflow = new Workflow();
         BeanUtils.copyProperties(workflowVo, workflow);
-        workflow.setDag(JacksonUtil.toJSONString(workflowVo.getDag()));
-        workflow.setGlobalParam(JsonUtils.objectToJson(workflowVo.getGlobalParam()));
+        if (workflowVo.getDag() != null) {
+            workflow.setDag(JacksonUtil.toJSONString(workflowVo.getDag()));
+        } else {
+            workflow.setDag(null);
+        }
+        if (workflowVo.getGlobalParam() != null) {
+            workflow.setGlobalParam(JsonUtils.objectToJson(workflowVo.getGlobalParam()));
+        } else {
+            workflow.setGlobalParam(null);
+        }
         LoginUser loginUser = SecurityUtils.getLoginUser();
         checkDeclaredName(workflow);
         workflow.setUpdateBy(loginUser.getUsername());